350 running rich

Hi I have an 88 350 TBI 1500 and i was wondering what would cause full fuel pressure when starting. When starting for instance the only way to get to start without flooding it is to unhook the plugs on the injectors after a minute then hook them back in when the engine is running. Even then it sounds to me like the engine is running really high even though I know the thermostat is stuck part way open because it only heats up to around 120F. I had to replace the distributor cap and rotor and also just put in new plugs. The old ones were severely fouled.

I just went out and checked the pressure valve and from what i can see there are no holes or excessive wear to the diaphragm. One thing i did notice though when i started it to move it the check engine light came on but it was running smoother and at a more normal idle speed. After a few minutes the light went out and the idle speed when up again.

A bad fp regulator can cause this or a bad coolant temp sensor which is more common.